Multiple volcanic domes. These require a favourable nearby placement of the terminator to obtain a good view.

Origin: Volcanic   Diameter: 70 km   Rukl: 28    Type: Dome

Objects: Mons Rümker, Oceanus Procellarum
Others: Mairan

Location: Home
Date: 2025-10-04
Time: 11:09 PM ADT
Equipment: 10" Meade SCT
Eyepiece: 22.5mm (on SvBony 10-30mm Zoom Eyepiece) with 2x Barlow

Magnification: x222
Seeing: Excellent (1)
Transparency: Excellent (1)

RI: Easy to find Oceanus Procellarum. Mons Rümker is west of the crater Mairan. The area is otherwise featureless. Seems to have an open end like a crescent-shaped bay. The Mons clearly rises from the Oceanus Procellarum floor.

C1: The diamond depression in central Mons Rümker created a shadow on the peak, its crease walls were well illuminated.